Resealable flow-wrap pack for wet wipes

ABSTRACT

The present invention relates to a flow-wrap pack for wet wipes. The flow-wrap pack has a film defining a front wall and a back wall, a longitudinal sealed seam in the form of a fin seal and two transverse sealed seams defining a product space. The fin seal has an extended length and lies essentially flat against the back wall of the wrap pack, thereby covering a scored tear line and a resealable strip, said strip extending between the transverse sealed seams at an essentially right angle to the transverse sealed seams.

The present invention relates to a flow-wrap pack for wet wipes.

Flow wrap packs are widely used for packaging various products, e.g. chocolate, biscuits, cakes, but also for household, hygiene or technical products. A typical household product is wet wipes which are small moistened pieces of paper or cloth. Wet wipes are typically used for household cleaning or for personal hygiene.

Flow-wrap packs comprise a film, e.g. a monolayer film or a multilayer film in the form of a laminate. The structure of the laminate depends on the properties desired with respect to the packaged product, e.g. in terms of a barrier effect against oxygen, moisture or light. Films used for flow-wrap packaging are usually produced and delivered to the packer in form of webs. In the course of the packaging the film is unrolled and wrapped around the product. In case a single item of a product is flow-wrap packed, the item is simply unwrapped when used. However, in cases where multiple items of a product, e.g. wet wipes, are flow-wrap packed, some kind of removal system is necessary. The removal system must allow the removal of a single item, and the reclosing of the flow-wrap pack to protect the remaining items, in the case of wet wipes against drying out. It is known to achieve such a removal system by introducing a cut in the flow-wrap pack that is torn open when an item is to be removed and the application of a label that allows reclosing the pack after the item has been removed. This is usually done by die cut operation and the application of a label, both steps have to be done by the packer in the course of the flow-wrap packaging. For the user such removal systems are quite awkward to deal with.

The object of the present invention is to provide a flow-wrap pack having a simple removal system that may be operated with a single hand and rendering the die cut operation and the label application unnecessary.

The object is achieved by a flow-wrap pack according to claim 1. Further preferred embodiments are subject to dependent claims.

A flow-wrap pack according to the present invention has a film. Said film defines a front wall and a back wall, a longitudinal sealed seam in the form of a fin seal and two transverse sealed seams, thereby defining a product space. The fin seal has an extended length and lies essentially flat against the back wall of the wrap pack. Thereby, the longitudinal sealed seam covers a scored tear line and a resealable strip. The resealable strip extends between the two transverse sealed seams and is arranged on the film at an essentially right angle to the transverse sealed seams.

The film of the wrap pack is folded or wrapped around the product in question in a way that the side edges of the film mate on the back side of the pack and are sealed in order to form the longitudinal seal. In the longitudinal direction the flow-wrap pack is closed by the two transverse sealed seams. Regarding the two transverse sealed seams the side of the film which is sealed is the side facing the product space. In the case of the fin seal there are two possibilities, either the film is folded in a way that the edges on the side of the film facing the product space mate and are sealed against each other or the film is folded back on its edges in a way that the outer side of the film, i.e. the side facing the outside of the package, mate and are sealed against each other.

Usually fin seals have a length of approximately 10 to 20 mm in order to provide a secure sealed seam without wasting material. It has been found that the fin seal may be extended in its length thereby providing a protective flap for the tear line which in turn provides an opening for the removal of single items once it is pushed through. The extended fin seal on the back wall of the flow-wrap pack, lying essentially flat against the back wall, protects the tear line and also covers the resealable strip. In order to remove a single item from the flow-wrap pack the extended fin seal is unfolded uncovering the tear line which is pushed through to reveal the first item. This allows a convenient opening and closing of the flow-wrap pack with a single hand. A label application by the packer allowing the reclosing of the flow-wrap pack is unnecessary, as well as the arrangement of a tear line by way of a die cut operation.

The resealable strip comprises means allowing the reclosing of the flow wrap pack. Said means may be a Velcro®, a fracture hot melt, a pressure sensitive adhesive or glue dots.

The resealable strip may optionally been covered by a peelable tape. The peelable tape renders the resealable strip inactive. Once the flow wrap pack is opened and the tear line is broken to remove a first item of the packed product, the tape is peeled off the resealable strip, the adhesive surface of the resealable strip is uncovered and allows securely reclosing the flow wrap pack when the extended fin seal is folded back in its position lying flat against the back wall.

The resealable strip is arranged at some distance to the tear line. When the extended fin seal is folded back to the back wall, it securely adheres to the resealable strip greatly reducing the risk that moisture leaking through the open tear line hampers the adhesive strength of the resealable strip. A disadvantage commonly encountered in flow wrap packs in the state of the art when an adhesive label is directly placed on an open tear line of such packs.

In a preferred embodiment of the flow-wrap pack the length of the fin seal with respect to the total width of the flow-wrap pack is in the range of 25% to 100%, preferably in the range of 40% to 60%, most preferably approximately 50%. The minimum length of an extended fin seal should be 40 mm. The fin seal is not necessarily arranged in the middle of the back wall of the flow-wrap pack. It may also be offset allowing the tear line to be arranged in the middle of the back wall of the pack.

In another embodiment there is a print layer arranged on at least a part of the front wall of the flow-wrap pack. The print layer may optionally be covered by a protective layer. Since the opening for the removal of an item of the packed product is arranged on the back wall of the flow wrap pack the print layer is advantageously a continuous print layer. Further, there is no need for a printed adhesive label matching the colours of the pack graphics. Flow wrap packs in the state of the art having a printed adhesive label covering the die cut opening often have the problem that the print is compromised due to colours and graphics that do not match since the print process for the pack graphics and the adhesive label are different.

In a further preferred embodiment the tear line extends between the two transverse sealed seams at an essentially right angle. The tear line may have different configurations. It may be a straight line, be an S-shaped line or an arched line (horseshoe). The S-shaped line is preferred and the arched line is more preferred. The length of the tear line regarding a straight line is preferably in the range of 40% to 60% of the total length of the flow wrap pack. If the tear line is curved the length of the tear line is related to its extension between the two side edges of the flow wrap pack.

In another preferred embodiment the resealable strip is covered by peelable tape. The peelable tape is peeled off when the first item is removed from the pack. When the peelable tape is removed a resealable strip is exposed which allows the protective flap, i.e. the fin seal, to be resealed until further items are to be removed.

In a further preferred embodiment the resealable strip comprises a pressure sensitive adhesive. Further types of adhesives that may be used are fracture hotmelt, cold seal lacquers, heat seal lacquers and glue dots. Pressure sensitive adhesives are preferred. An alternative fastening system is a hook and eye closure. Preferably the closing mean is selected from the group consisting of pressure sensitive adhesives, fracture hotmelt, cold seal lacquers, heat seal lacquers and glue dots.

In another preferred embodiment of the flow-wrap pack the film is a monolayer film or a multilayer film comprising polyolefin, polyester, polypropylene, polyethylene, polyamide, metalized plastics or silicon oxide (SiOx, whereby 1.3<x<1.9). Ethylene-vinylalcohol copolymer (EVOH) is a further polymer that can be used. The following examples are possible film structures having a multiple layers:

-   -   oPET/PE     -   oPP/oPET/PE     -   oPET/oPP/PE     -   oPET/oPET/PE     -   oPET/oPET/cPP

The abbreviations mean the following oPP: oriented polypropylene, oPET: oriented polyethylene terephthalate, PE: polyethylene, cPP: cast polypropylene.

Preferred film structures are:

-   -   oPP/PE     -   oPP/cPP     -   PET/PE     -   PET/cPP

The film structure oPP/PE is most preferred.

The above mentioned polymers may also be coextruded to form a monoweb comprising different resin layers.

In another preferred embodiment the tear line is introduced by laser scoring.

Laser scoring is a techniques that allows to achieve scores in a variety of flexible packaging materials. Laser scoring delivers a controlled score depth for easy open packaging while the film's barrier properties are maintained. Laser scoring is a non-contact technology creating precise scores having a well defined depth for easy open packaging features that consistently tear along the designated score lines. Laser score lines can be precisely registered to other features on the flow-wrap packs, e.g. a print, seamed seals etc. Further, score lines of almost any shape can be achieved. Materials that are suited for laser scoring are polyolefins, polyester, polyethylene, polypropylene, polyamides (nylon), and metalized films. Multilayer films are also well suited for laser scoring.

Mechanical scoring may also be employed. However, laser scoring is preferred.

A method for the production of the flow wrap pack is as follows: In a first step the different layers of the film are printed and subsequently laminated. The resealable strip and the tear line are arranged on the film. The tear line is preferably achieved by laser scoring. It may also be done by mechanical scoring. Then the film is slit to size into reels which are delivered to the packer of the flow wrapped product. The packer produces the final flow wrap pack employing the film in flow wrap pack machines.

The resealable flow-wrap pack for wet wipes according to the present invention is explained in more detail below with reference to exemplary embodiments in the drawings, in which, purely schematically:

FIG. 1 shows a flow-wrap pack from the prior art;

FIG. 2 shows a flow-wrap pack according to the present invention;

FIG. 3A shows a first embodiment of the flow-wrap pack;

FIG. 3B shows a second embodiment of the flow-wrap pack

FIG. 3C shows a third embodiment of the flow-wrap pack.

FIG. 4A shows a cross-sectional view of a further embodiment of the flow wrap pack;

FIG. 4B shows a cross-sectional view of a further embodiment of the flow wrap pack.

FIG. 1 shows a flow-wrap pack from the prior art. The flow-wrap pack 1 has film 3. Further, the back wall 7 and the longitudinal sealed seam 9 as well as the two transverse sealed seams 11 are shown. The longitudinal sealed seam is designed as usual. It is just long enough to provide for a secure sealing of the pack.

FIG. 2 shows a flow-wrap pack 1 according to the present invention. The flow-wrap pack 1 is shown from its back side. Thus the front wall which may comprise a print cannot be seen. The pack 1 has a film 3 that defines the front wall and the back wall 7. The extended longitudinal sealed seam 9 in the form of a fin seal which closes the flow-wrap pack on its back side lies essentially flat to the back wall 7. The two transverse sealed seams 11 close the flow-wrap pack 1 on its upper and lower end thereby defining a product space.

FIG. 3A shows the flow-wrap pack of FIG. 2 whereby the longitudinal sealed seam 9 in the form of a fin seal has been lifted in an upright position. The dashed line 17 indicates the position of the extended edge of the fin seal when it lies essentially flat against the back wall. Since the longitudinal sealed seam is removed from its flat in an upright position the tear line 13 and the resealable strip 15 can be seen. In this embodiment the tear line 13 has an arched shape (also termed horseshoe). The resealable strip 17 may covered by further a peelable tape (not shown) that is peeled off when the first item is removed from the pack in order to allow a reclosing of the flow-wrap pack 1 when the longitudinal sealed seam is folded over against the back wall 7 of the flow-wrap pack 1.

FIG. 3B shows a further configuration of the tear line 13. In this embodiment the tear line 13 has the shape of a straight line.

FIG. 3C shows a third embodiment of the flow-wrap pack 1 wherein the tear line 13 has an S-shape.

FIGS. 4A and 4B show a cross-sectional view of a further embodiment of the flow wrap pack. The embodiments show different possibilities of the fin seal (9) on the back of the flow wrap pack. FIG. 4A shows an embodiment where the inner side of the film (3) is sealed against each other. FIG. 4B shows an embodiment where a part of the film (3) is folded back in order to mate the outside of the film (3) which is sealed against each other. 

1. A flow-wrap pack for wet wipes having a film defining a front wall and a back wall, a longitudinal sealed seam in the form of a fin seal and two transverse sealed seams defining a product space, whereby the fin seal has an extended length and lies essentially flat against the back wall of the wrap pack, thereby covering a scored tear line and a resealable strip, the strip extending between the transverse sealed seams at an essentially right angle to the transverse sealed seams.
 2. The flow-wrap pack according to claim 1, wherein the length of the fin seal is in the range of 25% to 100% of a total pack width.
 3. The flow-wrap pack according to claim 1, wherein a print layer is arranged on at least on a part of the front wall and optionally a protective layer is arranged on top of the print layer.
 4. The flow-wrap pack according to claim 1, wherein the tear line extends between the transverse sealed seams at an essentially right angle to the transverse sealed seams.
 5. The flow-wrap pack according to claim 1, wherein the resealable strip is covered by a peelable tape.
 6. The flow-wrap pack according to claim 1, wherein the tear line is laser scored.
 7. The flow-wrap pack according to claim 1, wherein the tear line is a straight line or an S-shaped line or an arched line.
 8. The flow-wrap pack according to claim 1, wherein the resealable strip comprises an adhesive selected from the group consisting of fracture hotmelts, cold seal lacquers, heat seal lacquers, glues and pressure sensitive adhesive.
 9. The flow-wrap pack according to claim 1, wherein the resealable strip comprises a hook and eye closure.
 10. The flow-wrap pack according to claim 1, wherein the film is a monolayer film or a multilayer film comprising at least one of polyolefin, polyester, polypropylene, polyethylene, polyamide, ethylene-vinylalcohol copolymer, metalized plastics, or SiO_(x).
 11. The flow-wrap pack according to claim 10, wherein the film comprises a layer of oPP and a layer of PE.
 12. The flow-wrap pack according to claim 1, wherein the length of the fin seal is in the range of 40% to 60% of a total pack width.
 13. The flow-wrap pack according to claim 1, wherein the length of the fin seal is in the range of approximately 50% of a total pack width.
 14. The flow-wrap pack according to claim 1, wherein a print layer is arranged on at least on a part of the front wall and a protective layer is arranged on top of the print layer. 